Deployment Guide

5. Enter the linkcost command to set low cost values, ensuring that the cumulative ISL cost for the
selected path is lower than that of all other paths. A low cost path should have a cumulative ISL
cost of less than 10,000.
• In the following example, the ISL link cost of path 2 from FC router ID Domain 40 to FC router
Domain ID 30 is modified.
switch:admin>linkcost 10 5000
Interface10 (E_PORT) Cost 5000
• In the following example, the ISL link cost of path 2 from FC router Domain 30 to FC router
Domain 20 is modified.
switch:admin>linkcost 10 5000
Interface10 (E_PORT) Cost 5000
The modified cumulative link cost for path 2 is 10,000.
6. Enter the fcrConfigure --enable -shortestifl command to enable the shortest IFL mode in all the
FC routers in the backbone fabric.
switch:admin> fcrconfigure --enable -shortestifl
Shortest IFL path is enabled
7. Enter the fcrConfigure -show command to verify that the shortest IFL mode is enabled in all the
FC routers in the backbone fabric.
switch:admin> fcrconfigure --show
Backbone fabric ID: 128
Shortest IFL feature is enabled
8. Verify that the link cost of both the front domain and translate domain in the source edge fabric have
been modified using the lsDbShow command.
linkCnt = 2, flags = 0x0
LinkId = 160, out port = 160 rem port = 241, cost = 10001, costCnt = 0, type = 1
LinkId = 161, out port = 161, rem port = 242, cost = 10000, costCnt = 0, type =
1
EX_Port frame trunking configuration
EX_Port frame trunking provides the best utilization and balance of frames transmitted on each link
between the FC router and the edge fabric. You should trunk all ports connected to the same edge
fabrics.
You configure EX_Ports to use frame-based trunking just as you do regular E_Ports. The restrictions
for EX_Port frame trunking are the same as for E_Ports--all the ports must be adjacent to each other
using the clearly marked groups on the front of the product.
The FC router front domain has a higher node WWN--derived from the FC router--than that of the
edge fabric. Therefore, the FC router front domain initiates the trunking protocol on the EX_Port.
After initiation, the first port from the trunk group that comes online is designated as the master port.
The other ports that come online on the trunk group are considered the slave ports. Adding or
removing a slave port does not cause frame drop; however, removing a slave port causes the loss of
frames in transit.
If router port cost is used with EX_Port trunking, the master port and slave ports share the router port
cost of the master port.
For information about setting up E_Port trunking on an edge fabric, refer to Managing Trunking
Connections on page 509.
EX_Port frame trunking configuration
558 Fabric OS Administrators Guide
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